• Title/Summary/Keyword: dominant period

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Measurement of Carbonaceous Species in Fine Particles at Kosan, Cheju Island during the Two Summer Seasons of 1994 and 1995 (제주도 고산에서의 1994~1995년 여름 입자상 탄소농도 측정)

  • 이종훈;백남준;심상규;김용표
    • Journal of Korean Society for Atmospheric Environment
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    • v.13 no.3
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    • pp.179-191
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    • 1997
  • The concentrations of organic and elemental carbon were determined using fine particle samples collected from Kosan, Cheju Island during the summer seasons of 1994 and 1995. The daily mean concentrations of organic and elemental carbon for each measurement period were 3.74 and 0.27 $\mu\textrm{g}$/㎥ in 1994, while those of 1995 were 2.36 and 0.10 $\mu\textrm{g}$/㎥, respectively The concentrations of organic carbon were higher than those commonly observed from clean areas around the world, but those of elemental carbon were lower than, or comparable to, other clean areas in the world. The resulting ratios of total carbon to elemental carbon at this site were thus higher than those seen from other metropolitan and non-polluted regions abroad. In addition according to our analysis, the 1994 measurement period can be classified into two periods: enhanced (July 20 and August 1) and reduced levels (August 2 and 9) of the carbonaceous species. The observed difference between two periods may be in part accounted for by the air trajectories representing each period. During the former period, the air masses from the Asian continent and Japan were dominant, while the air masses from the North Pacific Ocean came during the latter period. OC/EC ratios at the site were calculated to predict the possible formation of secondary organic aerosol . Based on our observations, we suggest that the formation of secondary organic aerosol might be an important pathway to the production of organic carbons.

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Identification and Categorization of Jul Designs and Patterns in the Sāsānian Period

  • Davood, SHADLOU;Amir, SHADLOU
    • Acta Via Serica
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    • v.7 no.2
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    • pp.39-64
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    • 2022
  • Ancient Iranians highly esteemed the horse and horse tacks, one of which is the jul (saddlecloth). It is a felt, sheepskin, or woven pad placed between the horse's back and saddle. The aim of this paper is to identify and categorize jul designs in the Sāsānian period. The research questions are about the variety of jul designs and how to categorize them. This is fundamental research and the method is descriptive and analytical. Neither a jul nor a saddle-cover remains from the Sāsānian period, therefore the statistical population includes all available items, such as metal and stone items and parget and plasterworks, in which juls are recognizable. Due to the scarcity of such items, all the available samples were studied; so the sampling method is a total enumeration. This is documentary research by means of note-taking and using reliable websites; the data has been analyzed qualitatively. The results show that jul designs were not diverse in the Sāsānian period. All-over designs were dominant. In terms of pattern types, these designs are classified into five groups, each of which has its own formal and aesthetic characteristics: all-over design with a four-petal flower pattern, allover design with a checkered pattern, all-over design with a spotted pattern, allover design with a tiger stripe pattern, and all-over design with a zigzag pattern.

Seasonal Variation of the Phytoplankton Community and Physico-chemical Factors of Dong-stream in Jeollanam-do (전라남도 동천의 식물플랑크톤 군집 및 환경요인의 계절적 변이)

  • Kim, Yong-Jin;Shin, Hyun-Joo;Lee, Ok-Min
    • Journal of Korean Society on Water Environment
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    • v.29 no.2
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    • pp.223-231
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    • 2013
  • This study investigated the physio-chemical water quality and the standing crop of the phytoplankton of Dong-stream in Jeollanam-do from May 2010 to Feb 2011. The indicators and the dominant species of phytoplankton were also measured to investigate the water quality of estuary. Nutrients turned out to be eutrophic to hypertrophic in most sites with total nitrogen ranging 1.023~10.743 mg/L and total phosphorous ranging 0.0182~1.6848 mg/L. The site D6 had the highest BOD ranging 0.6~7.5 mg/L. Total of 205 taxa appeared within the research period, Bacillariophyceae being the highest number of taxa. The appeared species were taxa resistant to pollution including Navicula pupula, N. subminuscula, Nitzschia amphibia and N. palea. The downstream is thought to be greatly affected by the ocean water since marine and estuary phytoplankton such as Skeletonema costatum, Coscinodiscus radiatus, Bacteriastrum delicatulum and Eucampia biconcave appeared. Diatom appeared mainly as dominant species including Cymbella minuta, Melosira varians, Gomphonema parvulum, Stephanodiscus hantzschii. As for Stephanodiscus hantzschii, it dominates during fall and winter when the water temperature drops. Diatom showed 50% or higher dominant rate in all seasons at most sites. Most sites turned out to be eutrophic based on the standing crop of cells and chlorophyll a concentration. Total of 15 polluted water indicating taxa including Oscillatoria limosa appeared. From this result, the Dong-stream was considered to be in the eutrophication.

Macrozoobenthic Community on the Mud-tidalflat around Mokpo Coastal Area, Korea (목포 인근 해역 펄 조간대의 저서동물 군집)

  • 임현식;박경양;임병선;이점숙;주수동
    • The Korean Journal of Ecology
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    • v.20 no.5
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    • pp.355-365
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    • 1997
  • Macrozoobenthic community structure was studied on the mud-tidalflat around Mokpo coastal area, Korea, from September 1995 to May 1996. Ten sampling stations were chosen along the 1km transect with a 100 m intervals. Triple macrozoobenthos sampling were conducted with a stainless box core sampler (size $13{\times}22{\times}30$ cm) at each station on the seasonal basis. A total of 119 species of macrobenthos was sampled with a mean density 2,357 $ind./m^2$ and biomass of 180. 94 $g/m^2$ during the study period. Of these species, there were 51 species of mollusce (43%), 36 of crustaceans (30%), 27 of polychaetes (23%). Molluscs were density-dominant faunal group with a mean density of 1,804 $ind./m^2$, comprising of 75% of the total density of the benthic animals. It was followed by polychaetes with 347 $ind./m^2$ (15% of the total density). Molluscs were biomass-dominant faunal group with a mean biomass of 147.51 $g/m^2$ (82% of the total biomass). The number of species, abundance and biomass showed increasing trends toward the lower intertidal stations from the higher stations. Major dominant species were Musculista senhousia (bivalve), Capitellidae spp. (polychaetes) with a density of 1,640 $ind./m^2$ and 179 $ind./m^2$ , respectively. The density of M. senhousia was more than 63% of the total density of benthic organism on the tidal area. Small gastropod Cerithideopsilla umumriensis was another dominant epifaunal species between st.1 and 2 with a mean density of 100 $ind./m^2$. Cluster analysis showed that the benthic community could be divided into three stational groups, that is, upper, middle and lower groups by the exposure duration.

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Changes in the Community Structure of Fish Collected by a Gape Net with Wings in the Coastal Waters of Jindo Island in Response to a Cold Water Appearance in the Southwestern Sea of Korea (남해 서부해역 저수온수 출현에 따른 진도 연안 낭장망에 채집된 어류 군집구조 변화)

  • Yoo, Joon-Taek;Seong, Ki Tack;Kim, Yeong Hye
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.48 no.5
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    • pp.776-782
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    • 2015
  • We examined the community structure of fish off the coast of Jindo Island in response to a cold water appearance in the southwestern sea of Korea each August between 2013–2015. Using a gape net with wings, we collected 31 taxa during the study period, wherein the most dominant species was Engraulis japonicus. Collichthys lucidus and Neosalanx andersoni, which are mainly distributed in the western sea of Korea, increased in abundance and were dominant in August 2013, possibly due to the apparent intrusion of cold water (< 19°C) from offshore into the coastal waters of Jindo Island. Meanwhile, Scomberomorus niphonius and Sardinella zunasi, which are known as warmwater migratory species, increased in abundance and were dominant in August 2015, likely influenced by the warmer water (> 20°C) at the coast, which resulted in a noticeable lessening of the cold water in the study area. However, no significant differences were observed in fish community structure in the month of August between 2013–1015. This implies that the small-scale spatial and temporal variations in the cold water had limited effects on the fish community structure, even though the abundances of several dominant species varied in the coastal waters.

A Study on Fish Fauna and Fish Habitat -Downstream of Singok Submergerd Weir in Han River Estuary- (한강하구 생물자원 및 서식처 특성에 관한 연구 -신곡수중보 하류 한강하구의 어류상-)

  • Moon, Byeong Ryeol;Jeon, Sook Lye;Hyun, Moon Sik;Hwang, Jong Seo;Choi, Jun Kil
    • Journal of Environmental Impact Assessment
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    • v.20 no.5
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    • pp.757-764
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    • 2011
  • This study is performed to clarify the fish fauna and fish habitat of downstream of Singok submerged weir within Han River estuary during April ~ December 2009. It was studied at the nine sites of Han River estuary area. The three of them were located in the mainstream of Han River and six of them were located in three wetlands which as Sannam, Janghang and Dolbangguji. Total fish fauna was identified as 9 order 15 family and 38 species (2,230 individuals). It was divided as 8 order 11 family 28 species from three sites in the mainstream of Han River and as 5 order 8 family 19 species in waterways at mud flats of three wetlands. It was made up the fish fauna as 3 order 4 family 12 species during the survey period at the waterways in the rice paddies. Hemibarbus labeo was dominant species in the whole research sites and waterways at mud flats. Carassius auratus was dominant species in the waterways between rice paddies and Chelon haematocheilus was dominant species in mainstream of Han River estuary.

Altitudinal Distribution of Ants in Mt. Gariwangsan, Korea (가리왕산 지역의 개미 고도별 분포)

  • Cho, Kyoung-Yeon;Kim, Il-Kwon;Lyu, Dong-Pyeo
    • Korean Journal of Environment and Ecology
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    • v.34 no.2
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    • pp.115-120
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    • 2020
  • This study investigated the dominant species and the population variation of the ant species, an indicator species of biodiversity, to obtain basic data on the changes of population according to the future climate change. The survey period was from June to September 2013, and we investigated the distribution of ants by square irradiation method (10m × 10m) using traps. The survey in each altitude identified a total of 14 species of 11 genera in 3 subfamilies and collected 15,466 individuals. We confirmed the distribution of 4,548 individuals of 13 species at low altitude (700m), and the dominant species was Aphaenogaster japonica (49.9%). At the middle altitude (900m), we collected 9,129 individuals of 8 species, and the dominant species was Pheidole fervida (57.7%). At high altitude (1,100m), we identified 1,789 individuals of 10 species, and Myrmica kotokui (43.3%) was the dominant species. It was confirmed that Aphaenogaster japonica, Nylanderia flavipes, and Pheidole fervida were widely distributed throughout the altitudes.

Effect of Climate Change for Cyanobacteria Growth Pattern in Chudong Station of Lake Daechung (기후변화에 따른 대청호 추동지점에서의 남조류 발생 패턴 분석)

  • Noh, SungYu;Park, HaeKyung;Choi, HeeLak;Lee, JaeAn
    • Journal of Korean Society on Water Environment
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    • v.30 no.4
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    • pp.377-385
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    • 2014
  • To study the fluctuations and relationship in climate change, environmental factors and cyanobacteria communities, we investigated Chudong station of the Daechung reservoir. The average annual temperature showed the maximum value ($13.9^{\circ}C$) from 1994, showed a gradually increasing pattern from 1969 to 2010 in the Daechung reservoir. The number of days with temperatures over $20^{\circ}C$, minimum temperature of the year and average temperature of the winter season patterns also showed a significant increase. The long-time changed in the annual precipitation were not showed a significant variation. The water temperature record comparatively high value in summer, declined in winter. At all period, the phytoplankton were highest biomass in July 2000, and then, showed comparative higher biomass in the summer months. Cyanobacteria taxa were also showed more than 50%. Emergence of cyanobacteria also appeared in November 2007, were prolonged emergence. The dominant genera of taxa were the dominant sphere (Microcystis spp.) until early 2000. After that, the dominant species were the dominant linear (Aphanizomenon spp., Anabaena spp.). Cyanobacteria were the most correlated with water temperature (r = 0.341, p<0.01) and phosphate concentration (r = 0.355, p<0.01).

Effect of leg weight shifting on muscle activation of the trunk and lower extremity during trunk flexion and extension performance

  • Shim, Suyoung;Chung, Yijung
    • Physical Therapy Rehabilitation Science
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    • v.7 no.1
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    • pp.41-47
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    • 2018
  • Objective: To investigate the effect of performing three different toe touch (TT) task condition on the activities of four different muscles using surface electromyography (sEMG) in healthy young adults. Design: Cross-sectional study. Methods: A total of 20 healthy young adults (6 males, 14 females) voluntarily participated in this study. All subject randomly performed three different TT task conditions as follows: general toe-touch (GTT) task, one side toe touch (TT) task during weight bearing, and one side foward toe touch (FTT) task during weight bearing. The muscle activities of erector spinae (ES), gluteus maximus (GM), hamstring (HAM), tibialis anterior (TA) muscles during the TT task were measured using sEMG. Subject performed each of the three conditions three time in random order and mean values were obtained. Results: With the trunk flexion period, the TT and FTT showed significantly greater muscle activity in the GM, HAM and TA compared to the GTT task (p<0.05). The TT position showed significantly greater HAM muscle activity than the GTT position. The dominant and nondominant ES muscle activity was significantly greater in the FTT compared to the GTT position (p<0.05). The dominant GM, HAM, and TA was significantly greater in the TT and FTT compared to the GTT position (p<0.05). Although the dominant ES was significantly greater in the TT and FTT compared to the GTT position (p<0.05), the dominant GM muscle activity was signifcantly greater in the TT compared with the GTT position (p<0.05). Conclusions: These findings may be applicable within the clinical field for selective trunk and lower extremity muscle activation and basic biomechanics purpose.

Phytosociological Studios on Natural Vegetation in Hoo-Won, Changduk Palace (창경궁 후원 자연식생의 식물사회학적 연구)

  • 오구균;이경재
    • Journal of the Korean Institute of Landscape Architecture
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    • v.14 no.2
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    • pp.27-42
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    • 1986
  • The vegetation structure in the Hoo - Won, Changduk Palace in Seoul was analysed on 10 sites sampled for understanding structure of natural vegetation. The main vegetational survey was conducted during July, 1985 and actual vegetaion and degree of natural vegetaion types were surveyed additionally. The result summarized of this research are as follows. 1) The physical - chemical conditions of soil showed middle class. This might be derived by short succession period from Pine forest to decidious broadleaf forest and artificial impact by human intervention. 2) When considering dominance species by crown story, Quercus aliena was a dominant species over all site and Castanea crenata, Prunus sargentii and Quercus variabilis appeared as a dominant species locally at upper story. Styrax story and Rhododendron mucronulatum, Styrax japonica, Stephanandra incisa and Lespedeza spp. at lower story. 3) The distances kept by trees per crown story are as follows. The mean distances between trees were 4.5-5.5m at upper story, 2.8-3.3m at middle story. On the other hand, the mean distances between dominant species were 6-8m at upper story, 5-9m at middle story. 4) The vegetation in this area was not developed yet into dominant species community according to the similarity analysis. The natural vegetation was dominated by Quercus spp. especially Quercus aliena according to the analysis of species diversity, relative dominance by story and DBH class. On the orther hand, succession to climax stage dominated by shade tolerent species will take a long time due to little appearance of shade tolerence species by previous heavy artificial impacts on understory species. 5) Quercus forest took possesion of 71.3%(27.37ha) of total forest area when considering the actual vegetation and especially Quercus aliena community covered 53.2%(15.21ha). Carpinus laxiflora community, one of the climax species in temperate zone, took possesion of 1.0%(0.3ha) and Pine densiflora was almost disappeared due to species competition. 6) According to the degree of natural vegetation types, the possession of degree of 6-9 was 60.6% and degree of 7-8, substitute vegetation, was 15.5%. The possesion of degree of 9 which consists of over 50 years old trees simliar to natural vegetaion was the highest, 43.1% in this area. Therefore continuous protection in this area of degree of 9 should be recommended.

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